function testdct()
    p = zeros(8,8);
    for i = 1:8
        for j = 1:8
            q = p;
            q(i,j) = 255;
            qi = idct2(q,[8,8]);
            imshow(qi,[]);
            fname = sprintf('img%02dx%02d',i,j);
            disp(fname);
            print('-djpeg',fname);
        end
    end
end
